Finding Latitude Using a Tabletop Foucault Pendulum

The Foucault Pendulum has been around since Foucault demonstrated the effect in 1851, but they have needed to be many meters in length in order to precess correctly. The miniaturization of the Foucault Pendulum to something that can easily hang from any ceiling is desired for locations that do not have the space for the 10 meter tall standard length. Using an aluminum disk to remove an unwanted motion perpendicular to the swing and electromagnetic sense and drive coils to interact with a magnet on the pendulum bob we were able to counter the air drag and disk damping to keep it going indefinitely. The resultant pendulum and base (now on display in the physics lounge downstairs in West Science) can be used to demonstrate several basic physics phenomena including precession, eddy current damping, and inductance and magnetic fields.